Process for preparing glyphosate

Abstract

The invention discloses a new technology used to make glyphosate. It includes the following steps: weighting up each constituent according to the following mol ratio that methanol 3-10.5, tri-ethylamine 0.8-0.9, paraformaldehyde 1.95-2.05, glycine 1, dimethylphosphite 1.02-1.1, hydrochloric acid 2.9-3.34; de-polymerization that keeping the methanol, tri-ethylamine, and paraformaldehyde at 30-40 degree centigrade for 10-60min; adding glycine and keeping at 20-44 degree centigrade for 10-90min; condensation that adding dimethylphoshpite and keeping at 50-55 degree centigrade for 60-90min; acid hydrolysis that adding the composed liquid into hydrochloric acid and heating up to final 105-125 degree centigrade; crystallizing that producing glyphosate hydrochloride, then decompression, distillation, removing solvent methanol and excess hydrochloric acid. The produced glyphosate has the advantages of high yield, good quality, and low energy consumption.

Description

technical field

[0001] The invention relates to a production and preparation process of glyphosate. Background technique

[0002] Glyphosate is a non-selective, highly effective, low toxicity, broad systemic herbicide. It can be widely used in the control of crop weeds in tea gardens, orchards, rubber plantations, corn, sugarcane and forests, and can effectively remove hundreds of annual and perennial weeds. At present, the domestic preparation of glyphosate mostly adopts the alkyl acid method, that is, paraformaldehyde or formaldehyde is kept in a methanol solution containing triethylamine for 60 to 90 minutes at a temperature of 33°C to 40°C. Then add glycine into the solution by heating and dissolving, keep the temperature at 42°C for 90-120 minutes, then add dimethyl phosphite, carry out condensation reaction at 60-70°C, the reaction ends after 30-120 minutes, and then Add hydrochloric acid for acid hydrolysis. The hydrochloride of glyphosate is formed, and after the ...